What Vicor Corporation told the SEC could break it.

Vicor's revenue leans on a few accounts: one (unnamed) customer was ~11.1% of total net revenues in 2025 (12.1% in 2024, 10.7% in 2023). The concentration is sharper in its strategic Advanced Products line — since launch, the majority of Advanced Products revenue in any given year has come from either one customer or a limited number of customers (directly, via their contract manufacturers, or through royalties). Loss or pullback of a top account, or a slowing of Advanced Products design wins, would have an outsized effect. No counterparty named, so a register risk rather than a graph edge.

“Since the introduction of our Advanced Products, the Company has derived the majority of its revenue from Advanced Products in any given year from either one customer or a limited number of customers, whether through sales directly to the customer(s), indirectly to the customers' contract manufacturers, or through royalties.”

China (incl. Hong Kong) was ~11.9% of Vicor's net revenues in 2025 (12.6% in 2024, 17.7% in 2023), and over half of total revenue is international (50.8% in 2025). That China exposure sits against U.S. export controls aimed at restricting the PRC's access to advanced computing chips/supercomputers/advanced-semiconductor manufacturing — rules Vicor calls uncertain and evolving — which, given its power components feed AI/data-center systems, are a structural headwind to its China sales. Bridged to the China node.

“Net revenues from customers in China and Hong Kong, accounted for approximately 11.9% in 2025, approximately 12.6% in 2024, and approximately 17.7% in 2023 of our total net revenues.”

Vicor imports tariffed Chinese-origin goods (notably semiconductor content), and Section 301 China tariffs have had a material impact on profitability: ~$7.375M of tariff cost in 2025, up 76.1% from $4.189M in 2024 (and ~$7.985M in 2023), running roughly 1.8% of revenue in 2025. It responded by adding a 10% tariff surcharge to product prices in H2 2025 and filing duty-drawback claims with CBP to recover tariffs on raw materials used in subsequently-exported products (recovering $0.907M in 2025). A specific, quantified, ongoing trade-policy cost channel.

“However, the costs of Section 301 Tariffs have had a material impact on our profitability. For the year ended December 31, 2025, Section 301 Tariffs totaled approximately $7,375,000, an increase of 76.1% compared to $4,189,000 incurred for 2024.”

Vicor's most critical semiconductor devices are manufactured by a limited number of wafer foundries, with packaging and test by a limited number of third parties, and certain key components for Advanced Products are supplied by single vendors. It relies on these foundries/OSAT providers for supply continuity and carries elevated inventory (raw materials are ~76% / $69.6M of total inventory) to buffer long electronics-supply-chain lead times. An upstream foundry or single-vendor disruption would directly constrain its highest-value products. Suppliers unnamed → register risk.

“We rely on these wafer foundries and packaging and test providers for supply continuity of these critical semiconductor devices.”